If you plow through the thousands of posts on the Radian Pro thread, you will eventually run across some good advice, but that takes a lot of work.

I have flown a Radian Pro and have found that the rear of the fuselage requires stiffening or the plane does squirrely things under power, like going into a sudden dive. Some have put carbon fiber tubes in the wing to stiffen it.

Typical changes include a different and larger prop and a different battery. For ALES competitions, there is little advantage in powering up a Radian Pro beyond the power needed to get to the target altitude within the max time.